Charcoal is required to run a number of critical buildings: forges, casting boxes, Glazier's Benches, Toxin Kitchens, and some smelting facilities. It is also used in alchemy and in the creation of fireworks.
Charcoal is produced naturally as a byproduct of burning a bonfire, but it is more often manufactured in a Charcoal Hearth, Oven, or Brazier. The hearth is the easiest building to use, as it has a regulator which may be adjusted to slow the rate at which it operates. Ovens and braziers require somewhat more skill, but produce more charcoal per run.
A hearth can convert 50 wood into charcoal. An oven can convert 100 wood, and a brazier can convert 300 wood. All three require the base amount plus an initial 9 wood to start, and must be fed additional wood during the process.
Producing charcoal with bonfires requires more time, more clicking, and less wood.
Charcoal hearths, ovens, and braziers all operate similarly. There are six meters in the interface window: Heat, Oxygen, Wood, Water, Danger, and Progress. The goal is to fill the Progress meter to 100%. If Danger reaches 100%, the wood will catch fire and be lost. If Heat, Oxygen, or Wood falls to 0%, the fire will go out. When the Progress bar turns green, your charcoal is ready. You may extinguish the fire and collect your charcoal. The Main tab on the chat window provides commentary.
There are three controls: You may add wood, add water, or adjust the vent to one of three positions (closed, center, and open). The vent controls the rate at which oxygen enters the hearth: close the vent to lower the oxygen level and open it to raise it.
The following rules apply:
Note that oxygen both raises (by fueling the fire) and lowers (by cooling the hearth) the heat bar.
Hearths operate on a delayed feedback loop. If heat is rising, it tends to continue to rise; if falling, it tends to continue to fall.
Experienced charcoalers often operate several ovens at once.
Keep your Heat around 2/3… if it drops below ½ you will stop making progress! If it gets close to full then the charcoal will burst into flames and you will lose.
Use WOOD to control the level of heat. You want to keep the heat steady once you hit about 2/3, but if it drops below 2/3 put on one wood per tick until the heat level stabilizes again.
Keep your oxygen around 1/3. If it drops to 0 the fire will go out and you will lose. (more useful to say, don't have a closed vent when oxygen is less than 1/3. Having high oxygen is not bad! By closing the vent you will get a bit more heat, but don't let it distract you.)
Use the VENT to control the level of oxygen. Move the vent to the left to decrease the oxygen level. Move the vent to the right to increase the oxygen level. Keep the vent in the middle (you will do this most of the time) to keep the oxygen level steady.
WOOD has a minor effect on the oxy, VENT has a minor effect on the heat, but for starters you can just ignore those.
Remember: WOOD = heat, VENT = oxygen.
DON’T BE AFRAID TO PUT IN AS MUCH WOOD AS POSSIBLE, even to the point of filling the wood trough, when you see the heat level dropping. If you pay close enough attention, you will only need to put in 1 or 2 WOOD at a time to keep the heat level steady and about ½. Your goal is to NEVER have the heat level go below ½.
If the danger level gets to about 80%, put one WATER on the fire. This will kill the danger AND the heat will start dropping too, so follow up the WATER with one WOOD. You may occasionally have to put more than one water on the fire.
To decrease the danger level, close the vent all the way (far left position). This will also decrease the oxygen level as well, so occasionally you might have to use water instead of closing the vent.